1. Field of the Invention
The present invention relates to apparatus for the automatic fueling of automotive vehicles, and particularly to the refueling of cars.
2. Description of the Related Art
It is known to refuel, inter alia, buses automatically, with the aid of an industrial-type robot having a movable arm which carries a conventionally designed fueling nozzle or pistol on the free end thereof. The buses referred to are long-distance buses and are found in a few models and designs with respect to the position of the fuel pipe on the bus and the configuration of the fuel-pipe aperture or opening. Fueling was carried out indoors, in a building corresponding to a bus garage.
Swedish Patent Specification No. 8403564-1, which corresponds with U.S. Pat. No. 4,728,955, granted Mar. 1, 1988, describes a method and apparatus for determining the mutual position of two objects. This specification states that the invention can be applied conceivably for effecting automatic refueling of cars. The primary intention with the invention described in the prior specification is to enable the fueling pistol to be positioned relative to the fuel pipe of the car concerned. The specification describes a technique in which a transmitter/receiver device functions to transmit signals of microwave frequency to a so-called transponder, which is intended to reflect signals transmitted from the transmitter/receiver device back to said device. The transponder is preferably a so-called passive transponder which does not require an energy boost in order to transmit the signals received from the transmitter/receiver device. The invention described in the aforesaid Swedish Patent Specification can be applied advantageously together with the present invention, for positioning a unit corresponding to a fueling pistol in relation to the fuel pipe of an automotive vehicle, such as a car.
In apparatus intended for the automatic refueling of automotive vehicles, and then particularly cars, the primary problem is not one of achieving alignment of the fueling pistol with the fuel pipe, since the method and apparatus taught by the aforesaid Patent Specification are well suited for achieving mutual alignment of these two components in space to a predetermined position therebetween.
The problem concerned is a different problem, mainly that there is a very large number of different makes and models of cars and therewith innumerable variations in the position of the fuel pipe, its angle to the horizontal in two mutually perpendicular directions, the configuration of the upper portion of the pipe, i.e. the part of the pipe extending immediately from its mouth, and the diameter of said pipe.
Furthermore, the fuel-pipe connection also has many different configurations. These different variants in the design or configuration of various parts also present a problem of a different character, mainly that it must be guaranteed that fuel exiting from the fueling pistol will be deposited in the fuel tank of a vehicle and not on the ground beneath.
In brief, when fueling a vehicle automatically, the vehicle is driven to an unmanned petrol station and parked within a prescribed area of, e.g. 7.times.3 meters, with the side of the vehicle on which the fuel pipe is situated being positioned adjacent a fueling robot. The vehicle may be positioned with the aid of known devices, which are operative to indicate to the driver those vehicle-position changes which are necessary in order for the vehicle to be brought to a permitted, predetermined position in relation to the fueling robot. An example of one such known arrangement is described below. Subsequent to the vehicle having been brought to a predetermined position, there is activated a robot which functions to advance a fueling pistol, open the fuel-pipe closure device and establish a connection between the fueling pistol and the fuel pipe. Movement of the robot in a direction towards the vehicle fueling location, i.e., the location of the fuel pipe, and accurate alignment of the fueling pistol in relation to the fuel pipe can be controlled by means of an arrangement according to the aforesaid patent specification.
Subsequent to achieving said alignment, the robot is activated to pump fuel to the fueling pistol and down into the fuel tank of the vehicle through the fuel pipe. The fueling pistol is constructed to detect when the tank is full, in a known manner, and therewith interrupt the supply of fuel to the tank. The robot is then activated so as to move away from the fuel pipe, whereafter the fuel-pipe closure device must be reclosed.
It is obvious that it is difficult to guarantee that no fuel will be pumped onto the ground instead of into the fuel tank of the vehicle, in view of the fact that the vehicles are positioned with differing degrees of accuracy and because the vehicle components concerned in such fueling operations differ widely with respect to their design and configuration.
Furthermore, the fueling apparatus must be so constructed that if, for instance, a vehicle is driven away despite the fact that refueling has not been completed, no damage will occur to the robot or to the vehicle. The apparatus must also be able to function efficiently in widely varying climatic conditions.
Since the apparatus is intended to operate without the attendance of personnel, it is extremely important that the vital parts of the robot, and particularly the parts which establish connection between the fueling pistol and the fuel-pipe of the vehicle, do not become damaged by rough handling or by violent action. If these parts are damaged, fuel may well be poured onto the ground adjacent the vehicle.
The present invention resolves the aforesaid problems, among others, and provides apparatus well suited for the automatic fueling of vehicles.